<template>
            <div class="type-nav">
            <div class="container">
                <!-- 事件的委派 -->
              <div @mouseleave="leaveIndex" @mouseenter="enterShow">
                <h2 class="all">全部商品分类</h2>
                <!-- 过度动画 -->
                <transition name="sort">
                 <div class="sort" v-show="show">
                    <!-- 事件的委派 -->
                    <div class="all-sort-list2" @click="goSearch">
                        <div class="item" v-for="(c1,index) in categoryList.slice(0,16)" :key="c1.categoryId"
                        :class="{cur:currentIndex==index}">
                            <h3 @mouseenter="changeIndex(index)">
                                <a :data-categoryName="c1.categoryName" :data-category1Id="c1.categoryId"
                                >{{c1.categoryName}}</a>
                            </h3>
                            <div class="item-list clearfix" 
                            :style="{display:currentIndex == index?'block':'none'}">
                                <div class="subitem" v-for="(c2,index) in c1.categoryChild" :key="c2.categoryId">
                                    <dl class="fore">
                                        <dt>
                                           <a :data-categoryName="c2.categoryName" :data-category2Id="c2.categoryId"
                                           >{{c2.categoryName}}</a>
                                        </dt>
                                        <dd>
                                            <em v-for="(c3,index) in c2.categoryChild" :key="c3.categoryId">
                                                <a :data-categoryName="c3.categoryName" :data-category3Id="c3.categoryId"
                                                >{{c3.categoryName}}</a>
                                            </em>

                                        </dd>
                                    </dl>
                                </div>
                            </div>
                        </div> 
                    </div>
                </div>                   
                </transition>
              </div>
                <nav class="nav">
                    <a href="###">服装城</a>
                    <a href="###">美妆馆</a>
                    <a href="###">尚品汇超市</a>
                    <a href="###">全球购</a>
                    <a href="###">闪购</a>
                    <a href="###">团购</a>
                    <a href="###">有趣</a>
                    <a href="###">秒杀</a>
                </nav>
            </div>
        </div>
</template>

<script>
import { mapState } from 'vuex';
import throttle from 'lodash/throttle';

export default {
    name:'TypeNav',
    mounted() {
        //vuex发请求 存数据
        this.$store.dispatch('catgoryList')
        //如果不是home将TypeNav隐藏
        if(this.$route.path!='/home'){
            this.show =false
        }
    },
    data() {
        return {
            //存储用户鼠标移动分类
            currentIndex:-1,
            show:true
        }
    },
    computed:{
        ...mapState({
            //获取商品分类
            categoryList:(state)=>{
              return state.home.categoryList
            }                       
        })
    },
    methods: {
        //鼠标进入修改响应式数据
        changeIndex:throttle(function(index){
            this.currentIndex = index
        },50),
        //鼠标移除
        leaveIndex(){
            this.currentIndex =-1;
            if(this.$route.path!='/home'){               
                this.show = false;
            }

        },
        //跳转 最好用采用编程式导航+事件的委派
        goSearch(event){
            //a标签加入子节点categoryName
            //element获取事件触发的节点
            let element = event.target;
            // console.log(element)
            //节点有一个dataset属性值 可以获取节点的自定义属性和属性值
            let {categoryname,category1id,category2id,category3id} = element.dataset;
            // console.log(element.dataset)
            //获取自定义事件，可以确定如果有categoryname，那么一定是a标签
            if(categoryname){
                //整理路由跳转的参数
                let location = {name:'search'};
                let query ={categoryName:categoryname}
                //一级二级三级分类标签 获取category1id
                if(category1id){
                    // console.log(category1id)
                    query.category1Id =category1id;
                    // console.log(query)
                }else if(category2id){
                    query.category2Id =category2id;
                }else{
                    query.category3Id =category3id;
                }
                if(this.$route.params){
                    location.params = this.$route.params;
                    //整理参数 
                    //location动态添加query
                    location.query=query;
                    // console.log(location)               
                    //跳转 this.$router.push({name:"search",query:{categoryName:'xxx',1id；'XX'}});
                    this.$router.push(location);
                }

               
            }
        },
        //鼠标移入商品分类进行显示
        enterShow(){
            this.show = true;
        },

    },
}
</script>

<style lang="less" scoped>
        .type-nav {
        border-bottom: 2px solid #e1251b;

        .container {
            width: 1200px;
            margin: 0 auto;
            display: flex;
            position: relative;

            .all {
                width: 210px;
                height: 45px;
                background-color: #e1251b;
                line-height: 45px;
                text-align: center;
                color: #fff;
                font-size: 14px;
                font-weight: bold;
            }

            .nav {
                a {
                    height: 45px;
                    margin: 0 22px;
                    line-height: 45px;
                    font-size: 16px;
                    color: #333;
                }
            }

            .sort {
                position: absolute;
                left: 0;
                top: 45px;
                width: 210px;
                height: 461px;
                position: absolute;
                background: #fafafa;
                z-index: 999;

                .all-sort-list2 {
                    .item {

                        h3 {
                            line-height: 30px;
                            font-size: 14px;
                            font-weight: 400;
                            overflow: hidden;
                            padding: 0 20px;
                            margin: 0;

                            a {
                                color: #333;
                            }
                        }

                        .item-list {
                            display: none;
                            position: absolute;
                            width: 734px;
                            min-height: 460px;
                            background: #f7f7f7;
                            left: 210px;
                            border: 1px solid #ddd;
                            top: 0;
                            z-index: 9999 !important;

                            .subitem {
                                float: left;
                                width: 650px;
                                padding: 0 4px 0 8px;

                                dl {
                                    border-top: 1px solid #eee;
                                    padding: 6px 0;
                                    overflow: hidden;
                                    zoom: 1;

                                    &.fore {
                                        border-top: 0;
                                    }

                                    dt {
                                        float: left;
                                        width: 54px;
                                        line-height: 22px;
                                        text-align: right;
                                        padding: 3px 6px 0 0;
                                        font-weight: 700;
                                    }

                                    dd {
                                        float: left;
                                        width: 415px;
                                        padding: 3px 0 0;
                                        overflow: hidden;

                                        em {
                                            float: left;
                                            height: 14px;
                                            line-height: 14px;
                                            padding: 0 8px;
                                            margin-top: 5px;
                                            border-left: 1px solid #ccc;
                                        }
                                    }
                                }
                            }
                        }
                        // &:hover {
                        //     .item-list {
                        //         display: block;
                        //     }
                        // }
                    }
                    .cur{
                            background: skyblue;
                        }
                }
            }
            //过度动画进入样式
            .sort-enter{
                height:0px
                
            }
            //过度动画结束
            .sort-enter-to{
                height:461px
                
            }
            .sort-enter-active{
                transition: all .5s linear;
            }
        }
    }
</style>